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Ma YS, Deng SQ, Zhang P, Thomsen JS, Andreasen A, Chang SJ, Zhang J, Gu L, Zhai XY. Identification of countercurrent tubule-vessel arrangements in the early development of mouse kidney based on immunohistochemistry and computer-assisted 3D visualization. PLoS One 2024; 19:e0307223. [PMID: 39137214 PMCID: PMC11321558 DOI: 10.1371/journal.pone.0307223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 07/02/2024] [Indexed: 08/15/2024] Open
Abstract
Nephron loop-vessel countercurrent arrangement in the medulla provides the structural basis for the formation of concentrated urine. To date, the morphogenesis of it and relevant water and solutes transportation has not been fully elucidated. In this study, with immunohistochemistry for aquaporins (AQP) and Na-K-2Cl co-transporter (NKCC2), as well as 3D visualization, we noticed in embryonic day 14.5 kidneys that the countercurrent arrangement of two pairs of loop-vessel was established as soon as the loop and vessel both extended into the medulla. One pair happened between descending limb and ascending vasa recta, the other occurred between thick ascending limb and descending vasa recta. Meanwhile, the immunohistochemical results showed that the limb and vessel expressing AQP-1 such as descending thick and thin limb and descending vasa recta was always accompanied with AQP-1 negative ascending vasa recta or capillaries and thick ascending limb, respectively. Moreover, the thick ascending limb expressing NKCC2 closely contacted with descending vasa recta without expressing NKCC2. As kidney developed, an increasing number of loop-vessels in countercurrent arrangement extended into the interstitium of the medulla. In addition, we observed that the AQP-2 positive ureteric bud and their branches were separated from those pairs of tubule-vessels by a relatively large and thin-walled veins or capillaries. Thus, the present study reveals that the loop-vessel countercurrent arrangement is formed at the early stage of nephrogenesis, which facilitates the efficient transportation of water and electrolytes to maintain the medullary osmolality and to form a concentrated urine.
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Affiliation(s)
- Yun-Sheng Ma
- Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, Liaoning, China
- Department of Morphology, Medical College of Jinzhou Medical University, Jinzhou, Liaoning, China
| | - Si-Qi Deng
- Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, Liaoning, China
- Department of Pathology, the Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Ping Zhang
- Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, Liaoning, China
- Department of Morphology, Medical College of Jinzhou Medical University, Jinzhou, Liaoning, China
| | | | - Arne Andreasen
- Department of Biomedicine–Anatomy, Aarhus University, Aarhus, Denmark
| | - Shi-Jie Chang
- Department of Biomedical Engineering, School of Intelligent Medicine, China Medical University, Shenyang, Liaoning, China
| | - Jie Zhang
- Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, Liaoning, China
| | - Ling Gu
- Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, Liaoning, China
| | - Xiao-Yue Zhai
- Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, Liaoning, China
- Institute of Nephropathology, China Medical University, Shenyang, Liaoning, China
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2
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Siew K, Nestler KA, Nelson C, D'Ambrosio V, Zhong C, Li Z, Grillo A, Wan ER, Patel V, Overbey E, Kim J, Yun S, Vaughan MB, Cheshire C, Cubitt L, Broni-Tabi J, Al-Jaber MY, Boyko V, Meydan C, Barker P, Arif S, Afsari F, Allen N, Al-Maadheed M, Altinok S, Bah N, Border S, Brown AL, Burling K, Cheng-Campbell M, Colón LM, Degoricija L, Figg N, Finch R, Foox J, Faridi P, French A, Gebre S, Gordon P, Houerbi N, Valipour Kahrood H, Kiffer FC, Klosinska AS, Kubik A, Lee HC, Li Y, Lucarelli N, Marullo AL, Matei I, McCann CM, Mimar S, Naglah A, Nicod J, O'Shaughnessy KM, Oliveira LCD, Oswalt L, Patras LI, Lai Polo SH, Rodríguez-Lopez M, Roufosse C, Sadeghi-Alavijeh O, Sanchez-Hodge R, Paul AS, Schittenhelm RB, Schweickart A, Scott RT, Choy Lim Kam Sian TC, da Silveira WA, Slawinski H, Snell D, Sosa J, Saravia-Butler AM, Tabetah M, Tanuwidjaya E, Walker-Samuel S, Yang X, Yasmin, Zhang H, Godovac-Zimmermann J, Sarder P, Sanders LM, Costes SV, Campbell RAA, Karouia F, Mohamed-Alis V, Rodriques S, Lynham S, Steele JR, Baranzini S, Fazelinia H, Dai Z, Uruno A, Shiba D, Yamamoto M, A C Almeida E, Blaber E, Schisler JC, Eisch AJ, Muratani M, Zwart SR, Smith SM, Galazka JM, Mason CE, Beheshti A, Walsh SB. Cosmic kidney disease: an integrated pan-omic, physiological and morphological study into spaceflight-induced renal dysfunction. Nat Commun 2024; 15:4923. [PMID: 38862484 PMCID: PMC11167060 DOI: 10.1038/s41467-024-49212-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 05/28/2024] [Indexed: 06/13/2024] Open
Abstract
Missions into Deep Space are planned this decade. Yet the health consequences of exposure to microgravity and galactic cosmic radiation (GCR) over years-long missions on indispensable visceral organs such as the kidney are largely unexplored. We performed biomolecular (epigenomic, transcriptomic, proteomic, epiproteomic, metabolomic, metagenomic), clinical chemistry (electrolytes, endocrinology, biochemistry) and morphometry (histology, 3D imaging, miRNA-ISH, tissue weights) analyses using samples and datasets available from 11 spaceflight-exposed mouse and 5 human, 1 simulated microgravity rat and 4 simulated GCR-exposed mouse missions. We found that spaceflight induces: 1) renal transporter dephosphorylation which may indicate astronauts' increased risk of nephrolithiasis is in part a primary renal phenomenon rather than solely a secondary consequence of bone loss; 2) remodelling of the nephron that results in expansion of distal convoluted tubule size but loss of overall tubule density; 3) renal damage and dysfunction when exposed to a Mars roundtrip dose-equivalent of simulated GCR.
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Affiliation(s)
- Keith Siew
- London Tubular Centre, Department of Renal Medicine, University College London, London, UK.
| | - Kevin A Nestler
- The Institute for Biomedical Sciences (IBS), The George Washington University, Washington, DC, USA
| | - Charlotte Nelson
- Weill Institute for Neurosciences, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Viola D'Ambrosio
- London Tubular Centre, Department of Renal Medicine, University College London, London, UK
- Department of Experimental and Translational Medicine, Università Cattolica del Sacro Cuore di Roma, Rome, Italy
| | - Chutong Zhong
- London Tubular Centre, Department of Renal Medicine, University College London, London, UK
| | - Zhongwang Li
- London Tubular Centre, Department of Renal Medicine, University College London, London, UK
- Centre for Advanced Biomedical Imaging, University College London, London, UK
- Centre for Computational Medicine, University College London, London, UK
| | - Alessandra Grillo
- London Tubular Centre, Department of Renal Medicine, University College London, London, UK
| | - Elizabeth R Wan
- London Tubular Centre, Department of Renal Medicine, University College London, London, UK
| | - Vaksha Patel
- Department of Renal Medicine, University College London, London, UK
| | - Eliah Overbey
- Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY, USA
| | - JangKeun Kim
- Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY, USA
| | - Sanghee Yun
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Michael B Vaughan
- School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
- Tissue Engineering and Biomaterials Group, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Chris Cheshire
- Bioinformatics and Computational Biology Laboratory, The Francis Crick Institute, London, UK
| | - Laura Cubitt
- Applied Biotechnology Laboratory, The Francis Crick Institute, London, UK
| | - Jessica Broni-Tabi
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | | | - Valery Boyko
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Cem Meydan
- Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY, USA
| | - Peter Barker
- MRC MDU Mouse Biochemistry Laboratory, University of Cambridge, Cambridge, UK
| | - Shehbeel Arif
- Center for Data Driven Discovery in Biomedicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Division of Neurosurgery, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Fatemeh Afsari
- Department of Medicine-Nephrology & Intelligent Critical Care Center, University of Florida, Gainesville, FL, USA
| | - Noah Allen
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Mohammed Al-Maadheed
- Anti-Doping Laboratory Qatar, Doha, Qatar
- Centre of Metabolism and Inflammation, University College London, London, UK
| | - Selin Altinok
- School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Nourdine Bah
- Applied Biotechnology Laboratory, The Francis Crick Institute, London, UK
| | - Samuel Border
- Department of Medicine-Nephrology & Intelligent Critical Care Center, University of Florida, Gainesville, FL, USA
| | - Amanda L Brown
- Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Keith Burling
- MRC MDU Mouse Biochemistry Laboratory, University of Cambridge, Cambridge, UK
| | - Margareth Cheng-Campbell
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
- Blue Marble Space Institute of Science, Seattle, WA, USA
| | - Lorianna M Colón
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA, USA
| | - Lovorka Degoricija
- KBR, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Nichola Figg
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Rebecca Finch
- School of Health, Science and Wellbeing, Staffordshire University, Stoke-on-Trent, UK
| | - Jonathan Foox
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY, USA
| | - Pouya Faridi
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Alison French
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Samrawit Gebre
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Peter Gordon
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Nadia Houerbi
- Physiology, Biophysics & Systems Biology, Weill Cornell Medical College, New York, NY, USA
| | - Hossein Valipour Kahrood
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
- Monash Bioinformatics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Frederico C Kiffer
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Aleksandra S Klosinska
- Division of Experimental Medicine & Immunotherapeutics (EMIT), Department of Medicine, University of Cambridge, Cambridge, UK
| | - Angela Kubik
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Han-Chung Lee
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Yinghui Li
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, China
| | - Nicholas Lucarelli
- Department of Medicine-Nephrology & Intelligent Critical Care Center, University of Florida, Gainesville, FL, USA
| | - Anthony L Marullo
- School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Irina Matei
- Cornell Center for Immunology, Cornell University, Ithaca, NY, USA
- Children's Cancer and Blood Foundation Laboratories, Departments of Pediatrics and Cell and Developmental Biology, Drukier Institute for Children's Health, Meyer Cancer Center, Weill Cornell Medical College, New York, NY, USA
| | - Colleen M McCann
- Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sayat Mimar
- Department of Medicine-Nephrology & Intelligent Critical Care Center, University of Florida, Gainesville, FL, USA
| | - Ahmed Naglah
- Department of Medicine-Nephrology & Intelligent Critical Care Center, University of Florida, Gainesville, FL, USA
| | - Jérôme Nicod
- Advanced Sequencing Facility, The Francis Crick Institute, London, UK
| | - Kevin M O'Shaughnessy
- Division of Experimental Medicine & Immunotherapeutics (EMIT), Department of Medicine, University of Cambridge, Cambridge, UK
| | | | - Leah Oswalt
- Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - San-Huei Lai Polo
- KBR, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | | | - Candice Roufosse
- Department of Immunology and Inflammation, Imperial College London, London, UK
| | | | | | - Anindya S Paul
- Department of Medicine-Nephrology & Intelligent Critical Care Center, University of Florida, Gainesville, FL, USA
| | - Ralf Bernd Schittenhelm
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Annalise Schweickart
- Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY, USA
- Englander Institute for Precision Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Ryan T Scott
- KBR, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Terry Chin Choy Lim Kam Sian
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Willian A da Silveira
- School of Health, Science and Wellbeing, Staffordshire University, Stoke-on-Trent, UK
- International Space University, 67400, Illkirch-Graffenstaden, France
| | - Hubert Slawinski
- Advanced Sequencing Facility, The Francis Crick Institute, London, UK
| | - Daniel Snell
- Advanced Sequencing Facility, The Francis Crick Institute, London, UK
| | - Julio Sosa
- University Health Network, Toronto, ON, Canada
| | | | - Marshall Tabetah
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN, USA
| | - Erwin Tanuwidjaya
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Simon Walker-Samuel
- Centre for Advanced Biomedical Imaging, University College London, London, UK
- Centre for Computational Medicine, University College London, London, UK
| | | | - Yasmin
- Division of Experimental Medicine & Immunotherapeutics (EMIT), Department of Medicine, University of Cambridge, Cambridge, UK
| | - Haijian Zhang
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | | | - Pinaki Sarder
- Department of Medicine-Quantitative Health Section, University of Florida, Gainesville, FL, USA
- Departments of Biomedical Engineering and Electrical and Computer Engineering, University of Florida, Gainesville, FL, USA
| | - Lauren M Sanders
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
- Blue Marble Space Institute of Science, Seattle, WA, USA
| | - Sylvain V Costes
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Robert A A Campbell
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - Fathi Karouia
- Blue Marble Space Institute of Science, Seattle, WA, USA
- Space Research Within Reach, San Francisco, CA, USA
- Center for Space Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Vidya Mohamed-Alis
- Anti-Doping Laboratory Qatar, Doha, Qatar
- Centre of Metabolism and Inflammation, University College London, London, UK
| | - Samuel Rodriques
- Applied Biotechnology Laboratory, The Francis Crick Institute, London, UK
| | | | - Joel Ricky Steele
- Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Sergio Baranzini
- Weill Institute for Neurosciences, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Hossein Fazelinia
- Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA, USA
| | - Zhongquan Dai
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, China
| | - Akira Uruno
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Miyagi, Japan
| | - Dai Shiba
- Mouse Epigenetics Project, ISS/Kibo experiment, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki, Japan
- JEM Utilization Center, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki, Japan
| | - Masayuki Yamamoto
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Miyagi, Japan
- Department of Medical Biochemistry, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan
| | - Eduardo A C Almeida
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Elizabeth Blaber
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
- Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
- Stanley Center for Psychiatric Research, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | - Jonathan C Schisler
- Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Amelia J Eisch
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Masafumi Muratani
- Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Sara R Zwart
- Department of Preventative Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, USA
| | | | - Jonathan M Galazka
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY, USA
- The WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medical College, New York, NY, USA
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY, USA
| | - Afshin Beheshti
- KBR, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
- Broad Institute, Cambridge, MA, USA
- Space Biosciences Division, Universities Space Research Association (USRA), Washington, DC, USA
| | - Stephen B Walsh
- London Tubular Centre, Department of Renal Medicine, University College London, London, UK.
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Kumaran GK, Hanukoglu I. Mapping the cytoskeletal architecture of renal tubules and surrounding peritubular capillaries in the kidney. Cytoskeleton (Hoboken) 2024; 81:227-237. [PMID: 37937511 DOI: 10.1002/cm.21809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/02/2023] [Accepted: 11/06/2023] [Indexed: 11/09/2023]
Abstract
The human kidney includes ~1 million nephrons which are long U-shaped tubules with convoluted segments that serve as filtration units. During the passage of the ultrafiltrate through a nephron, electrolytes and nutrients are re-absorbed into peritubular capillaries. The fluid remaining in the distal end of the renal tubules flows through the collecting ducts into the ureter. In this study, we generated high-resolution images of mouse kidney sections using confocal microscopy with only two fluorescently tagged biomarkers, F-actin binding phalloidin and CD34 antibodies as a marker for blood vessels. In tile-scan images of entire sections of mouse kidney (composed of >1000 images), the tubule segments are easily identifiable by their F-actin bundles on cell borders and the outlines of the peritubular capillaries by CD34 immunofluorescence. In the inner stripe of the medulla, the vascular bundles composed of vasa recta (straight vessels) could be easily distinguished from the peritubular capillaries by their full circular shapes. The highly vascular inner medulla and the papilla similarly have straight capillaries. About 95% of kidney volume is composed of renal tubules and blood vessels. Thus, our results show that relatively simple cytoskeletal mapping can be used to visualize the structural organization of the kidney. This method can also be applied to examine pathological changes in the kidney.
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Affiliation(s)
| | - Israel Hanukoglu
- Laboratory of Cell Biology, Ariel University, Ariel, Israel
- Etgar College of Engineering and Technology, Tel Aviv, Israel
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4
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Habas E, Al Adab A, Arryes M, Alfitori G, Farfar K, Habas AM, Akbar RA, Rayani A, Habas E, Elzouki A. Anemia and Hypoxia Impact on Chronic Kidney Disease Onset and Progression: Review and Updates. Cureus 2023; 15:e46737. [PMID: 38022248 PMCID: PMC10631488 DOI: 10.7759/cureus.46737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2023] [Indexed: 12/01/2023] Open
Abstract
Chronic kidney disease (CKD) is caused by hypoxia in the renal tissue, leading to inflammation and increased migration of pathogenic cells. Studies showed that leukocytes directly sense hypoxia and respond by initiating gene transcription, encoding the 2-integrin adhesion molecules. Moreover, other mechanisms participate in hypoxia, including anemia. CKD-associated anemia is common, which induces and worsens hypoxia, contributing to CKD progression. Anemia correction can slow CKD progression, but it should be cautiously approached. In this comprehensive review, the underlying pathophysiology mechanisms and the impact of renal tissue hypoxia and anemia in CKD onset and progression will be reviewed and discussed in detail. Searching for the latest updates in PubMed Central, Medline, PubMed database, Google Scholar, and Google search engines were conducted for original studies, including cross-sectional studies, cohort studies, clinical trials, and review articles using different keywords, phrases, and texts such as "CKD progression, anemia in CKD, CKD, anemia effect on CKD progression, anemia effect on CKD progression, and hypoxia and CKD progression". Kidney tissue hypoxia and anemia have an impact on CKD onset and progression. Hypoxia causes nephron cell death, enhancing fibrosis by increasing interstitium protein deposition, inflammatory cell activation, and apoptosis. Severe anemia correction improves life quality and may delay CKD progression. Detection and avoidance of the risk factors of hypoxia prevent recurrent acute kidney injury (AKI) and reduce the CKD rate. A better understanding of kidney hypoxia would prevent AKI and CKD and lead to new therapeutic strategies.
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Affiliation(s)
| | - Aisha Al Adab
- Internal Medicine, Hamad General Hospital, Doha, QAT
| | - Mehdi Arryes
- Internal Medicine, Hamad General Hospital, Doha, QAT
| | | | | | - Ala M Habas
- Internal Medicine, Tripoli University, Tripoli, LBY
| | - Raza A Akbar
- Internal Medicine, Hamad General Hospital, Doha, QAT
| | - Amnna Rayani
- Hemat-oncology Department, Pediatric Tripoli Hospital, Tripoli University, Tripoli, LBY
| | - Eshrak Habas
- Internal Medicine, Tripoli University, Tripoli, LBY
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Nitric Oxide Signalling in Descending Vasa Recta after Hypoxia/Re-Oxygenation. Int J Mol Sci 2022; 23:ijms23137016. [PMID: 35806018 PMCID: PMC9266395 DOI: 10.3390/ijms23137016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 01/27/2023] Open
Abstract
Reduced renal medullary oxygen supply is a key factor in the pathogenesis of acute kidney injury (AKI). As the medulla exclusively receives blood through descending vasa recta (DVR), dilating these microvessels after AKI may help in renoprotection by restoring renal medullary blood flow. We stimulated the NO-sGC-cGMP signalling pathway in DVR at three different levels before and after hypoxia/re-oxygenation (H/R). Rat DVR were isolated and perfused under isobaric conditions. The phosphodiesterase 5 (PDE5) inhibitor sildenafil (10−6 mol/L) impaired cGMP degradation and dilated DVR pre-constricted with angiotensin II (Ang II, 10−6 mol/L). Dilations by the soluble guanylyl cyclase (sGC) activator BAY 60-2770 as well as the nitric oxide donor sodium nitroprusside (SNP, 10−3 mol/L) were equally effective. Hypoxia (0.1% O2) augmented DVR constriction by Ang II, thus potentially aggravating tissue hypoxia. H/R left DVR unresponsive to sildenafil, yet sGC activation by BAY 60-2770 effectively dilated DVR. Dilation to SNP under H/R is delayed. In conclusion, H/R renders PDE5 inhibition ineffective in dilating the crucial vessels supplying the area at risk for hypoxic damage. Stimulating sGC appears to be the most effective in restoring renal medullary blood flow after H/R and may prove to be the best target for maintaining oxygenation to this vulnerable area of the kidney.
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Super-Resolution Ultrasound Imaging Can Quantify Alterations in Microbubble Velocities in the Renal Vasculature of Rats. Diagnostics (Basel) 2022; 12:diagnostics12051111. [PMID: 35626267 PMCID: PMC9140053 DOI: 10.3390/diagnostics12051111] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/04/2022] [Accepted: 04/27/2022] [Indexed: 11/17/2022] Open
Abstract
Super-resolution ultrasound imaging, based on the localization and tracking of single intravascular microbubbles, makes it possible to map vessels below 100 µm. Microbubble velocities can be estimated as a surrogate for blood velocity, but their clinical potential is unclear. We investigated if a decrease in microbubble velocity in the arterial and venous beds of the renal cortex, outer medulla, and inner medulla was detectable after intravenous administration of the α1-adrenoceptor antagonist prazosin. The left kidneys of seven rats were scanned with super-resolution ultrasound for 10 min before, during, and after prazosin administration using a bk5000 ultrasound scanner and hockey-stick probe. The super-resolution images were manually segmented, separating cortex, outer medulla, and inner medulla. Microbubble tracks from arteries/arterioles were separated from vein/venule tracks using the arterial blood flow direction. The mean microbubble velocities from each scan were compared. This showed a significant prazosin-induced velocity decrease only in the cortical arteries/arterioles (from 1.59 ± 0.38 to 1.14 ± 0.31 to 1.18 ± 0.33 mm/s, p = 0.013) and outer medulla descending vasa recta (from 0.70 ± 0.05 to 0.66 ± 0.04 to 0.69 ± 0.06 mm/s, p = 0.026). Conclusively, super-resolution ultrasound imaging makes it possible to detect and differentiate microbubble velocity responses to prazosin simultaneously in the renal cortical and medullary vascular beds.
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Song T, Markham KK, Li Z, Muller KE, Greenham K, Kuang R. Detecting spatially co-expressed gene clusters with functional coherence by graph-regularized convolutional neural network. Bioinformatics 2022; 38:1344-1352. [PMID: 34864909 DOI: 10.1093/bioinformatics/btab812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 10/29/2021] [Accepted: 11/29/2021] [Indexed: 01/05/2023] Open
Abstract
MOTIVATION Clustering spatial-resolved gene expression is an essential analysis to reveal gene activities in the underlying morphological context by their functional roles. However, conventional clustering analysis does not consider gene expression co-localizations in tissue for detecting spatial expression patterns or functional relationships among the genes for biological interpretation in the spatial context. In this article, we present a convolutional neural network (CNN) regularized by the graph of protein-protein interaction (PPI) network to cluster spatially resolved gene expression. This method improves the coherence of spatial patterns and provides biological interpretation of the gene clusters in the spatial context by exploiting the spatial localization by convolution and gene functional relationships by graph-Laplacian regularization. RESULTS In this study, we tested clustering the spatially variable genes or all expressed genes in the transcriptome in 22 Visium spatial transcriptomics datasets of different tissue sections publicly available from 10× Genomics and spatialLIBD. The results demonstrate that the PPI-regularized CNN constantly detects gene clusters with coherent spatial patterns and significantly enriched by gene functions with the state-of-the-art performance. Additional case studies on mouse kidney tissue and human breast cancer tissue suggest that the PPI-regularized CNN also detects spatially co-expressed genes to define the corresponding morphological context in the tissue with valuable insights. AVAILABILITY AND IMPLEMENTATION Source code is available at https://github.com/kuanglab/CNN-PReg. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Tianci Song
- Department of Computer Science and Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55414, USA
| | - Kathleen K Markham
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Minneapolis, MN 55414, USA
| | - Zhuliu Li
- Department of Computer Science and Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55414, USA
| | - Kristen E Muller
- Department of Pathology and Laboratory Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - Kathleen Greenham
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Minneapolis, MN 55414, USA
| | - Rui Kuang
- Department of Computer Science and Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55414, USA
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8
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Computed Tomography Image under Three-Dimensional Reconstruction Algorithm Based in Diagnosis of Renal Tumors and Retroperitoneal Laparoscopic Partial Nephrectomy. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:3066930. [PMID: 34659683 PMCID: PMC8514888 DOI: 10.1155/2021/3066930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/28/2021] [Accepted: 08/31/2021] [Indexed: 11/30/2022]
Abstract
This study was to explore the clinical application value of computed tomography (CT) images based on a three-dimensional (3D) reconstruction algorithm for laparoscopic partial nephrectomy (LPN) in patients with renal tumors. 30 cases of renal cell carcinoma (RCC) patients admitted to the hospital were selected as the research objects and were rolled into two groups using a random table method. The patients who received PLN under the three-dimensional reconstruction and laparoscopic technique were included in the experimental group (group A), and the patients who received LPN using CT images only were included in the control group (group B). In addition, the treatment results of the two groups of patients were compared and analyzed. Results. The effective rate of the established model was 93.3%; the total renal arteriovenous variability of group A (13.3%) was higher than that of group B (6.7%), and the operation time (131.5 ± 32.1 minutes) was much lower than that of group B (158.7 ± 36.2 minutes), showing statistical significance (P < 0.05). Conclusion. CT images based on 3D reconstruction algorithms had high clinical application value for LPN in patients with renal tumors, which could improve the efficiency and safety of LPN.
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9
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Evans RG, Smith DW, Lee C, Ngo JP, Gardiner BS. What Makes the Kidney Susceptible to Hypoxia? Anat Rec (Hoboken) 2019; 303:2544-2552. [DOI: 10.1002/ar.24260] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/24/2019] [Accepted: 05/13/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Roger G. Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology Monash University Melbourne Victoria Australia
| | - David W. Smith
- Faculty of Engineering and Mathematical Sciences The University of Western Australia Perth Western Australia Australia
| | - Chang‐Joon Lee
- Faculty of Engineering and Mathematical Sciences The University of Western Australia Perth Western Australia Australia
- College of Science, Health, Engineering and Education Murdoch University Perth Western Australia Australia
| | - Jennifer P. Ngo
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology Monash University Melbourne Victoria Australia
| | - Bruce S. Gardiner
- Faculty of Engineering and Mathematical Sciences The University of Western Australia Perth Western Australia Australia
- College of Science, Health, Engineering and Education Murdoch University Perth Western Australia Australia
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10
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Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
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Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
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11
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Zhang P, Gu L, Cong J, Zhang J, Thomsen JS, Andreasen A, Chang SJ, Deng SQ, Xing J, Zhai XY. Morphology of the initial nephron-collecting duct connection in mice using computerized 3D tracing and electron microscopy. Biochem Biophys Res Commun 2019; 509:114-118. [DOI: 10.1016/j.bbrc.2018.12.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 12/11/2018] [Indexed: 11/16/2022]
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12
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Nawata CM, Pannabecker TL. Mammalian urine concentration: a review of renal medullary architecture and membrane transporters. J Comp Physiol B 2018; 188:899-918. [PMID: 29797052 PMCID: PMC6186196 DOI: 10.1007/s00360-018-1164-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 04/23/2018] [Accepted: 05/14/2018] [Indexed: 01/10/2023]
Abstract
Mammalian kidneys play an essential role in balancing internal water and salt concentrations. When water needs to be conserved, the renal medulla produces concentrated urine. Central to this process of urine concentration is an osmotic gradient that increases from the corticomedullary boundary to the inner medullary tip. How this gradient is generated and maintained has been the subject of study since the 1940s. While it is generally accepted that the outer medulla contributes to the gradient by means of an active process involving countercurrent multiplication, the source of the gradient in the inner medulla is unclear. The last two decades have witnessed advances in our understanding of the urine-concentrating mechanism. Details of medullary architecture and permeability properties of the tubules and vessels suggest that the functional and anatomic relationships of these structures may contribute to the osmotic gradient necessary to concentrate urine. Additionally, we are learning more about the membrane transporters involved and their regulatory mechanisms. The role of medullary architecture and membrane transporters in the mammalian urine-concentrating mechanism are the focus of this review.
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Affiliation(s)
- C Michele Nawata
- Department of Physiology, Banner University Medical Center, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ, 85724-5051, USA.
| | - Thomas L Pannabecker
- Department of Physiology, Banner University Medical Center, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ, 85724-5051, USA
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13
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Zhang J, Cong J, Yang J, Thomsen JS, Andreasen A, Chang SJ, Wang KY, Gu L, Zhai XY. Morphologic and morphometric study on microvasculature of developing mouse kidneys. Am J Physiol Renal Physiol 2018; 315:F852-F860. [DOI: 10.1152/ajprenal.00615.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A proper morphogenesis of the renal microvasculature is crucial not only for fulfilling the renal function but also to slow down the progression of chronic kidney disease in adulthood. However, the current description of the developing microvasculature is incomplete. The present study investigated the morphogenesis and volume densities of the renal microvasculature using computer-assisted tubular tracing, immunohistochemistry for CD34, and unbiased stereology. The earliest glomerular capillaries were observed at the lower cleft of the S-shaped nephrons, as simple loops connecting the afferent and efferent arterioles. In parallel with this, the peritubular capillaries were established. Noticeably, from early nephrogenesis on, the efferent arterioles of the early-formed glomeruli ran in close proximity to their own thick ascending limbs. In addition, the ascending vasa recta arising from the arcuate or interlobular veins also ran in close proximity to the thick descending limb. Thus, the tubules and vessels formed the typical countercurrent relation in the medulla. No loop bends were observed between descending and ascending vasa recta. The volume density of the cortical and medullary peritubular capillary increased 3.3- and 2.6-fold, respectively, from 2.34 (0.13) and 7.03 (0.09)% [means (SD)] at embryonic day 14.5 (E14.5) to 7.71 (0.44) and 18.27 (1.17)% at postnatal day 40 (P40). In contrast, the volume density of glomeruli changed only slightly during kidney development, from 4.61 (0.47)% at E14.5 to 6.07 (0.2)% at P7 to 4.19 (0.47)% at P40. These results reflect that the growth and formation of the renal microvasculature closely correspond to functional development of the tubules.
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Affiliation(s)
- Jie Zhang
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | - Jing Cong
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
- Department of Histology and Embryology, Shenyang Medical College, Shenyang, China
| | - Jie Yang
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | | | - Arne Andreasen
- Department of Biomedicine-Anatomy, Aarhus University, Aarhus, Denmark
| | - Shi-Jie Chang
- Department of Biomedical Engineering, College of Fundamental Science, China Medical University, Shenyang, China
| | - Kai-Yue Wang
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | - Ling Gu
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
| | - Xiao-Yue Zhai
- Department of Histology and Embryology, Basic Medicine College, China Medical University, Shenyang, China
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14
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Hinze C, Ruffert J, Walentin K, Himmerkus N, Nikpey E, Tenstad O, Wiig H, Mutig K, Yurtdas ZY, Klein JD, Sands JM, Branchi F, Schumann M, Bachmann S, Bleich M, Schmidt-Ott KM. GRHL2 Is Required for Collecting Duct Epithelial Barrier Function and Renal Osmoregulation. J Am Soc Nephrol 2017; 29:857-868. [PMID: 29237740 DOI: 10.1681/asn.2017030353] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 11/09/2017] [Indexed: 12/31/2022] Open
Abstract
Collecting ducts make up the distal-most tubular segments of the kidney, extending from the cortex, where they connect to the nephron proper, into the medulla, where they release urine into the renal pelvis. During water deprivation, body water preservation is ensured by the selective transepithelial reabsorption of water into the hypertonic medullary interstitium mediated by collecting ducts. The collecting duct epithelium forms tight junctions composed of barrier-enforcing claudins and exhibits a higher transepithelial resistance than other segments of the renal tubule exhibit. However, the functional relevance of this strong collecting duct epithelial barrier is unresolved. Here, we report that collecting duct-specific deletion of an epithelial transcription factor, grainyhead-like 2 (GRHL2), in mice led to reduced expression of tight junction-associated barrier components, reduced collecting duct transepithelial resistance, and defective renal medullary accumulation of sodium and other osmolytes. In vitro, Grhl2-deficient collecting duct cells displayed increased paracellular flux of sodium, chloride, and urea. Consistent with these effects, Grhl2-deficient mice had diabetes insipidus, produced dilute urine, and failed to adequately concentrate their urine after water restriction, resulting in susceptibility to prerenal azotemia. These data indicate a direct functional link between collecting duct epithelial barrier characteristics, which appear to prevent leakage of interstitial osmolytes into urine, and body water homeostasis.
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Affiliation(s)
- Christian Hinze
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,Departments of Nephrology and Medical Intensive Care
| | - Janett Ruffert
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Berlin Institute of Urologic Research, Berlin, Germany
| | - Katharina Walentin
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Nina Himmerkus
- Institute of Physiology, Christian Albrechts University Kiel, Kiel, Germany
| | - Elham Nikpey
- Department of Biomedicine, University of Bergen, Bergen, Norway.,Department of Medicine, Haukeland University Hospital, Bergen, Norway; and
| | - Olav Tenstad
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Helge Wiig
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Zeliha Yesim Yurtdas
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Berlin Institute of Urologic Research, Berlin, Germany
| | - Janet D Klein
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia
| | - Jeff M Sands
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia
| | - Federica Branchi
- Gastroenterology, Infectious Diseases and Rheumatology, Charité Universitätsmedizin, Berlin, Germany
| | - Michael Schumann
- Gastroenterology, Infectious Diseases and Rheumatology, Charité Universitätsmedizin, Berlin, Germany
| | | | - Markus Bleich
- Institute of Physiology, Christian Albrechts University Kiel, Kiel, Germany
| | - Kai M Schmidt-Ott
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; .,Departments of Nephrology and Medical Intensive Care
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15
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Cheng CJ, Rodan AR, Huang CL. Emerging Targets of Diuretic Therapy. Clin Pharmacol Ther 2017; 102:420-435. [PMID: 28560800 DOI: 10.1002/cpt.754] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/15/2017] [Accepted: 05/21/2017] [Indexed: 12/14/2022]
Abstract
Diuretics are commonly prescribed for treatment in patients with hypertension, edema, or heart failure. Studies on hypertensive and salt-losing disorders and on urea transporters have contributed to better understanding of mechanisms of renal salt and water reabsorption and their regulation. Proteins involved in the regulatory pathways are emerging targets for diuretic and aquaretic therapy. Integrative high-throughput screening, protein structure analysis, and chemical modification have identified promising agents for preclinical testing in animals. These include WNK-SPAK inhibitors, ClC-K channel antagonists, ROMK channel antagonists, and pendrin and urea transporter inhibitors. We discuss the potential advantages and side effects of these potential diuretics.
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Affiliation(s)
- C-J Cheng
- Department of Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, 114, Taiwan
| | - A R Rodan
- Department of Medicine, Division of Nephrology, University of Utah, Salt Lake City, Utah, USA
| | - C-L Huang
- Department of Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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16
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Letts RFR, Zhai XY, Bhikha C, Grann BL, Blom NB, Thomsen JS, Rubin DM, Christensen EI, Andreasen A. Nephron morphometry in mice and rats using tomographic microscopy. Am J Physiol Renal Physiol 2017; 312:F210-F229. [DOI: 10.1152/ajprenal.00207.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 09/21/2016] [Accepted: 10/03/2016] [Indexed: 11/22/2022] Open
Abstract
The aim was to quantify the glomerular capillary surface area, the segmental tubular radius, length, and area of single nephrons in mouse and rat kidneys. Multiple 2.5-µm-thick serial Epon sections were obtained from three mouse and three rat kidneys for three-dimensional reconstruction of the nephron tubules. Micrographs were aligned for each kidney, and 359 nephrons were traced and their segments localized. Thirty mouse and thirty rat nephrons were selected for further investigation. The luminal radius of each segment was determined by two methods. The luminal surface area was estimated from the radius and length of each segment. High-resolution micrographs were recorded for five rat glomeruli, and the capillary surface area determined. The capillary volume and surface area were corrected for glomerular shrinkage. A positive correlation was found between glomerular capillary area and proximal tubule area. The thickest part of the nephron, i.e., the proximal tubule, was followed by the thinnest part of the nephron, i.e., the descending thin limb, and the diameters of the seven identified nephron segments share the same rank in the two species. The radius and length measurements from mouse and rat nephrons generally share the same pattern; rat tubular radius-to-mouse tubular radius ratio ≈ 1.47, and rat tubular length-to-mouse tubular length ratio ≈ 2.29, suggesting relatively longer tubules in the rat. The detailed tables of mouse and rat glomerular capillary area and segmental radius, length, and area values may be used to enhance understanding of the associated physiology, including existing steady-state models of the urine-concentrating mechanism.
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Affiliation(s)
- Robyn F. R. Letts
- Biomedical Engineering Research Group in the School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, South Africa
| | - Xiao-Yue Zhai
- Department of Histology and Embryology, China Medical University, Shenyang, People’s Republic of China; and
| | - Charita Bhikha
- Biomedical Engineering Research Group in the School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, South Africa
| | - Birgitte L. Grann
- Department of Biomedicine–Anatomy, Aarhus University, Aarhus, Denmark
| | - Nicklas B. Blom
- Department of Biomedicine–Anatomy, Aarhus University, Aarhus, Denmark
| | | | - David M. Rubin
- Biomedical Engineering Research Group in the School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Arne Andreasen
- Department of Histology and Embryology, China Medical University, Shenyang, People’s Republic of China; and
- Department of Biomedicine–Anatomy, Aarhus University, Aarhus, Denmark
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17
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Hsi RS, Ramaswamy K, Ho SP, Stoller ML. The origins of urinary stone disease: upstream mineral formations initiate downstream Randall's plaque. BJU Int 2016; 119:177-184. [PMID: 27306864 DOI: 10.1111/bju.13555] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To describe a new hypothesis for the initial events leading to urinary stones. A biomechanical perspective on Randall's plaque formation through form and function relationships is applied to functional units within the kidney, we have termed the 'medullo-papillary complex' - a dynamic relationship between intratubular and interstitial mineral aggregates. METHODS A complete MEDLINE search was performed to examine the existing literature on the anatomical and physiological relationships in the renal medulla and papilla. Sectioned human renal medulla with papilla from radical nephrectomy specimens were imaged using a high resolution micro X-ray computed tomography. The location, distribution, and density of mineral aggregates within the medullo-papillary complex were identified. RESULTS Mineral aggregates were seen proximally in all specimens within the outer medulla of the medullary complex and were intratubular. Distal interstitial mineralisation at the papillary tip corresponding to Randall's plaque was not seen until a threshold of proximal mineralisation was observed. Mineral density measurements suggest varied chemical compositions between the proximal intratubular (330 mg/cm3 ) and distal interstitial (270 mg/cm3 ) deposits. A review of the literature revealed distinct anatomical compartments and gradients across the medullo-papillary complex that supports the empirical observations that proximal mineralisation triggers distal Randall's plaque formation. CONCLUSION The early stone event is initiated by intratubular mineralisation of the renal medullary tissue leading to the interstitial mineralisation that is observed as Randall's plaque. We base this novel hypothesis on a multiscale biomechanics perspective involving form and function relationships, and empirical observations. Additional studies are needed to validate this hypothesis.
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Affiliation(s)
- Ryan S Hsi
- Department of Urology, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - Krishna Ramaswamy
- Department of Urology, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - Sunita P Ho
- Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - Marshall L Stoller
- Department of Urology, School of Dentistry, University of California San Francisco, San Francisco, CA, USA
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18
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Wei G, Rosen S, Dantzler WH, Pannabecker TL. Architecture of the human renal inner medulla and functional implications. Am J Physiol Renal Physiol 2015; 309:F627-37. [PMID: 26290371 DOI: 10.1152/ajprenal.00236.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/10/2015] [Indexed: 11/22/2022] Open
Abstract
The architecture of the inner stripe of the outer medulla of the human kidney has long been known to exhibit distinctive configurations; however, inner medullary architecture remains poorly defined. Using immunohistochemistry with segment-specific antibodies for membrane fluid and solute transporters and other proteins, we identified a number of distinctive functional features of human inner medulla. In the outer inner medulla, aquaporin-1 (AQP1)-positive long-loop descending thin limbs (DTLs) lie alongside descending and ascending vasa recta (DVR, AVR) within vascular bundles. These vascular bundles are continuations of outer medullary vascular bundles. Bundles containing DTLs and vasa recta lie at the margins of coalescing collecting duct (CD) clusters, thereby forming two regions, the vascular bundle region and the CD cluster region. Although AQP1 and urea transporter UT-B are abundantly expressed in long-loop DTLs and DVR, respectively, their expression declines with depth below the outer medulla. Transcellular water and urea fluxes likely decline in these segments at progressively deeper levels. Smooth muscle myosin heavy chain protein is also expressed in DVR of the inner stripe and the upper inner medulla, but is sparsely expressed at deeper inner medullary levels. In rodent inner medulla, fenestrated capillaries abut CDs along their entire length, paralleling ascending thin limbs (ATLs), forming distinct compartments (interstitial nodal spaces; INSs); however, in humans this architecture rarely occurs. Thus INSs are relatively infrequent in the human inner medulla, unlike in the rodent where they are abundant. UT-B is expressed within the papillary epithelium of the lower inner medulla, indicating a transcellular pathway for urea across this epithelium.
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Affiliation(s)
- Guojun Wei
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, Arizona; and
| | - Seymour Rosen
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - William H Dantzler
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, Arizona; and
| | - Thomas L Pannabecker
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, Arizona; and
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19
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Pannabecker TL, Layton AT. Targeted delivery of solutes and oxygen in the renal medulla: role of microvessel architecture. Am J Physiol Renal Physiol 2014; 307:F649-55. [PMID: 25056344 DOI: 10.1152/ajprenal.00276.2014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Renal medullary function is characterized by corticopapillary concentration gradients of various molecules. One example is the generally decreasing axial gradient in oxygen tension (Po2). Another example, found in animals in the antidiuretic state, is a generally increasing axial solute gradient, consisting mostly of NaCl and urea. This osmolality gradient, which plays a principal role in the urine concentrating mechanism, is generally considered to involve countercurrent multiplication and countercurrent exchange, although the underlying mechanism is not fully understood. Radial oxygen and solute gradients in the transverse dimension of the medullary parenchyma have been hypothesized to occur, although strong experimental evidence in support of these gradients remains lacking. This review considers anatomic features of the renal medulla that may impact the formation and maintenance of oxygen and solute gradients. A better understanding of medullary architecture is essential for more clearly defining the compartment-to-compartment flows taken by fluid and molecules that are important in producing axial and radial gradients. Preferential interactions between nephron and vascular segments provide clues as to how tubular and interstitial oxygen flows contribute to safeguarding active transport pathways in renal function in health and disease.
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Affiliation(s)
- Thomas L Pannabecker
- Department of Physiology, College of Medicine, University of Arizona, Tucson, Arizona; and
| | - Anita T Layton
- Department of Mathematics, Duke University, Durham, North Carolina
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20
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Christensen EI, Grann B, Kristoffersen IB, Skriver E, Thomsen JS, Andreasen A. Three-dimensional reconstruction of the rat nephron. Am J Physiol Renal Physiol 2014; 306:F664-71. [PMID: 24477686 DOI: 10.1152/ajprenal.00522.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
This study gives a three-dimensional (3D) structural analysis of rat nephrons and their connections to collecting ducts. Approximately 4,500 2.5-μm-thick serial sections from the renal surface to the papillary tip were obtained from each of 3 kidneys of Wistar rats. Digital images were recorded and aligned into three image stacks and traced from image to image. Short-loop nephrons (SLNs), long-loop nephrons (LLNs), and collecting ducts (CDs) were reconstructed in 3D. We identified a well-defined boundary between the outer stripe and the inner stripe of the outer medulla corresponding to the transition of descending thick limbs to descending thin limbs and between the inner stripe and the inner medulla, i.e., the transition of ascending thin limbs into ascending thick limbs of LLNs. In all nephrons, a mosaic pattern of proximal tubule (PT) cells and descending thin limb (DTL) cells was observed at the transition between the PT and the DTL. The course of the LLNs revealed tortuous proximal "straight" tubules and winding of the DTLs within the outer half of the inner stripe. The localization of loop bends of SLNs in the inner stripe of the outer medulla and the bends of LLNs in the inner medulla reflected the localization of their glomeruli; i.e., the deeper the glomerulus, the deeper the bend. Each CD drained approximately three to six nephrons with a different pattern than previously established in mice. This information will provide a basis for evaluation of structural changes within nephrons as a result of physiological or pharmaceutical intervention.
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Affiliation(s)
- Erik I Christensen
- Dept. of Biomedicine, Anatomy Section of Cell Biology, Univ. of Aarhus, DK-8000 Aarhus C, Denmark.
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Pallone TL. Complex vascular bundles, thick ascending limbs, and aquaporins: wringing out the outer medulla. Am J Physiol Renal Physiol 2013; 306:F505-6. [PMID: 24370589 DOI: 10.1152/ajprenal.00663.2013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Thomas L Pallone
- Div. of Nephrology, N3W143, 22 S. Greene St., Univ. of Maryland Medical System, Baltimore, MD 21201.
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